// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/websockets/websocket_frame.h"

#include <algorithm>
#include <stdint.h>
#include <vector>

#include "base/macros.h"
#include "base/memory/aligned_memory.h"
#include "net/base/net_errors.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace net {

namespace {

    TEST(WebSocketFrameHeaderTest, FrameLengths)
    {
        struct TestCase {
            const char* frame_header;
            size_t frame_header_length;
            uint64_t frame_length;
        };
        static const TestCase kTests[] = {
            { "\x81\x00", 2, UINT64_C(0) },
            { "\x81\x7D", 2, UINT64_C(125) },
            { "\x81\x7E\x00\x7E", 4, UINT64_C(126) },
            { "\x81\x7E\xFF\xFF", 4, UINT64_C(0xFFFF) },
            { "\x81\x7F\x00\x00\x00\x00\x00\x01\x00\x00", 10, UINT64_C(0x10000) },
            { "\x81\x7F\x7F\xFF\xFF\xFF\xFF\xFF\xFF\xFF", 10,
                UINT64_C(0x7FFFFFFFFFFFFFFF) }
        };
        static const int kNumTests = arraysize(kTests);

        for (int i = 0; i < kNumTests; ++i) {
            WebSocketFrameHeader header(WebSocketFrameHeader::kOpCodeText);
            header.final = true;
            header.payload_length = kTests[i].frame_length;

            std::vector<char> expected_output(
                kTests[i].frame_header,
                kTests[i].frame_header + kTests[i].frame_header_length);
            std::vector<char> output(expected_output.size());
            EXPECT_EQ(static_cast<int>(expected_output.size()),
                WriteWebSocketFrameHeader(
                    header, NULL, &output.front(), output.size()));
            EXPECT_EQ(expected_output, output);
        }
    }

    TEST(WebSocketFrameHeaderTest, FrameLengthsWithMasking)
    {
        static const char kMaskingKey[] = "\xDE\xAD\xBE\xEF";
        static_assert(
            arraysize(kMaskingKey) - 1 == WebSocketFrameHeader::kMaskingKeyLength,
            "incorrect masking key size");

        struct TestCase {
            const char* frame_header;
            size_t frame_header_length;
            uint64_t frame_length;
        };
        static const TestCase kTests[] = {
            { "\x81\x80\xDE\xAD\xBE\xEF", 6, UINT64_C(0) },
            { "\x81\xFD\xDE\xAD\xBE\xEF", 6, UINT64_C(125) },
            { "\x81\xFE\x00\x7E\xDE\xAD\xBE\xEF", 8, UINT64_C(126) },
            { "\x81\xFE\xFF\xFF\xDE\xAD\xBE\xEF", 8, UINT64_C(0xFFFF) },
            { "\x81\xFF\x00\x00\x00\x00\x00\x01\x00\x00\xDE\xAD\xBE\xEF", 14,
                UINT64_C(0x10000) },
            { "\x81\xFF\x7F\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xDE\xAD\xBE\xEF", 14,
                UINT64_C(0x7FFFFFFFFFFFFFFF) }
        };
        static const int kNumTests = arraysize(kTests);

        WebSocketMaskingKey masking_key;
        std::copy(kMaskingKey,
            kMaskingKey + WebSocketFrameHeader::kMaskingKeyLength,
            masking_key.key);

        for (int i = 0; i < kNumTests; ++i) {
            WebSocketFrameHeader header(WebSocketFrameHeader::kOpCodeText);
            header.final = true;
            header.masked = true;
            header.payload_length = kTests[i].frame_length;

            std::vector<char> expected_output(
                kTests[i].frame_header,
                kTests[i].frame_header + kTests[i].frame_header_length);
            std::vector<char> output(expected_output.size());
            EXPECT_EQ(static_cast<int>(expected_output.size()),
                WriteWebSocketFrameHeader(
                    header, &masking_key, &output.front(), output.size()));
            EXPECT_EQ(expected_output, output);
        }
    }

    TEST(WebSocketFrameHeaderTest, FrameOpCodes)
    {
        struct TestCase {
            const char* frame_header;
            size_t frame_header_length;
            WebSocketFrameHeader::OpCode opcode;
        };
        static const TestCase kTests[] = {
            { "\x80\x00", 2, WebSocketFrameHeader::kOpCodeContinuation },
            { "\x81\x00", 2, WebSocketFrameHeader::kOpCodeText },
            { "\x82\x00", 2, WebSocketFrameHeader::kOpCodeBinary },
            { "\x88\x00", 2, WebSocketFrameHeader::kOpCodeClose },
            { "\x89\x00", 2, WebSocketFrameHeader::kOpCodePing },
            { "\x8A\x00", 2, WebSocketFrameHeader::kOpCodePong },
            // These are undefined opcodes, but the builder should accept them anyway.
            { "\x83\x00", 2, 0x3 },
            { "\x84\x00", 2, 0x4 },
            { "\x85\x00", 2, 0x5 },
            { "\x86\x00", 2, 0x6 },
            { "\x87\x00", 2, 0x7 },
            { "\x8B\x00", 2, 0xB },
            { "\x8C\x00", 2, 0xC },
            { "\x8D\x00", 2, 0xD },
            { "\x8E\x00", 2, 0xE },
            { "\x8F\x00", 2, 0xF }
        };
        static const int kNumTests = arraysize(kTests);

        for (int i = 0; i < kNumTests; ++i) {
            WebSocketFrameHeader header(kTests[i].opcode);
            header.final = true;
            header.payload_length = 0;

            std::vector<char> expected_output(
                kTests[i].frame_header,
                kTests[i].frame_header + kTests[i].frame_header_length);
            std::vector<char> output(expected_output.size());
            EXPECT_EQ(static_cast<int>(expected_output.size()),
                WriteWebSocketFrameHeader(
                    header, NULL, &output.front(), output.size()));
            EXPECT_EQ(expected_output, output);
        }
    }

    TEST(WebSocketFrameHeaderTest, FinalBitAndReservedBits)
    {
        struct TestCase {
            const char* frame_header;
            size_t frame_header_length;
            bool final;
            bool reserved1;
            bool reserved2;
            bool reserved3;
        };
        static const TestCase kTests[] = {
            { "\x81\x00", 2, true, false, false, false },
            { "\x01\x00", 2, false, false, false, false },
            { "\xC1\x00", 2, true, true, false, false },
            { "\xA1\x00", 2, true, false, true, false },
            { "\x91\x00", 2, true, false, false, true },
            { "\x71\x00", 2, false, true, true, true },
            { "\xF1\x00", 2, true, true, true, true }
        };
        static const int kNumTests = arraysize(kTests);

        for (int i = 0; i < kNumTests; ++i) {
            WebSocketFrameHeader header(WebSocketFrameHeader::kOpCodeText);
            header.final = kTests[i].final;
            header.reserved1 = kTests[i].reserved1;
            header.reserved2 = kTests[i].reserved2;
            header.reserved3 = kTests[i].reserved3;
            header.payload_length = 0;

            std::vector<char> expected_output(
                kTests[i].frame_header,
                kTests[i].frame_header + kTests[i].frame_header_length);
            std::vector<char> output(expected_output.size());
            EXPECT_EQ(static_cast<int>(expected_output.size()),
                WriteWebSocketFrameHeader(
                    header, NULL, &output.front(), output.size()));
            EXPECT_EQ(expected_output, output);
        }
    }

    TEST(WebSocketFrameHeaderTest, InsufficientBufferSize)
    {
        struct TestCase {
            uint64_t payload_length;
            bool masked;
            size_t expected_header_size;
        };
        static const TestCase kTests[] = {
            { UINT64_C(0), false, 2u },
            { UINT64_C(125), false, 2u },
            { UINT64_C(126), false, 4u },
            { UINT64_C(0xFFFF), false, 4u },
            { UINT64_C(0x10000), false, 10u },
            { UINT64_C(0x7FFFFFFFFFFFFFFF), false, 10u },
            { UINT64_C(0), true, 6u },
            { UINT64_C(125), true, 6u },
            { UINT64_C(126), true, 8u },
            { UINT64_C(0xFFFF), true, 8u },
            { UINT64_C(0x10000), true, 14u },
            { UINT64_C(0x7FFFFFFFFFFFFFFF), true, 14u }
        };
        static const int kNumTests = arraysize(kTests);

        for (int i = 0; i < kNumTests; ++i) {
            WebSocketFrameHeader header(WebSocketFrameHeader::kOpCodeText);
            header.final = true;
            header.opcode = WebSocketFrameHeader::kOpCodeText;
            header.masked = kTests[i].masked;
            header.payload_length = kTests[i].payload_length;

            char dummy_buffer[14];
            // Set an insufficient size to |buffer_size|.
            EXPECT_EQ(
                ERR_INVALID_ARGUMENT,
                WriteWebSocketFrameHeader(
                    header, NULL, dummy_buffer, kTests[i].expected_header_size - 1));
        }
    }

    TEST(WebSocketFrameTest, MaskPayload)
    {
        struct TestCase {
            const char* masking_key;
            uint64_t frame_offset;
            const char* input;
            const char* output;
            size_t data_length;
        };
        static const TestCase kTests[] = {
            { "\xDE\xAD\xBE\xEF", 0, "FooBar", "\x98\xC2\xD1\xAD\xBF\xDF", 6 },
            { "\xDE\xAD\xBE\xEF", 1, "FooBar", "\xEB\xD1\x80\x9C\xCC\xCC", 6 },
            { "\xDE\xAD\xBE\xEF", 2, "FooBar", "\xF8\x80\xB1\xEF\xDF\x9D", 6 },
            { "\xDE\xAD\xBE\xEF", 3, "FooBar", "\xA9\xB1\xC2\xFC\x8E\xAC", 6 },
            { "\xDE\xAD\xBE\xEF", 4, "FooBar", "\x98\xC2\xD1\xAD\xBF\xDF", 6 },
            { "\xDE\xAD\xBE\xEF", 42, "FooBar", "\xF8\x80\xB1\xEF\xDF\x9D", 6 },
            { "\xDE\xAD\xBE\xEF", 0, "", "", 0 },
            { "\xDE\xAD\xBE\xEF", 0, "\xDE\xAD\xBE\xEF", "\x00\x00\x00\x00", 4 },
            { "\xDE\xAD\xBE\xEF", 0, "\x00\x00\x00\x00", "\xDE\xAD\xBE\xEF", 4 },
            { "\x00\x00\x00\x00", 0, "FooBar", "FooBar", 6 },
            { "\xFF\xFF\xFF\xFF", 0, "FooBar", "\xB9\x90\x90\xBD\x9E\x8D", 6 },
        };
        static const int kNumTests = arraysize(kTests);

        for (int i = 0; i < kNumTests; ++i) {
            WebSocketMaskingKey masking_key;
            std::copy(kTests[i].masking_key,
                kTests[i].masking_key + WebSocketFrameHeader::kMaskingKeyLength,
                masking_key.key);
            std::vector<char> frame_data(kTests[i].input,
                kTests[i].input + kTests[i].data_length);
            std::vector<char> expected_output(kTests[i].output,
                kTests[i].output + kTests[i].data_length);
            MaskWebSocketFramePayload(masking_key,
                kTests[i].frame_offset,
                frame_data.empty() ? NULL : &frame_data.front(),
                frame_data.size());
            EXPECT_EQ(expected_output, frame_data);
        }
    }

    // Check that all combinations of alignment, frame offset and chunk size work
    // correctly for MaskWebSocketFramePayload(). This is mainly used to ensure that
    // vectorisation optimisations don't break anything. We could take a "white box"
    // approach and only test the edge cases, but since the exhaustive "black box"
    // approach runs in acceptable time, we don't have to take the risk of being
    // clever.
    //
    // This brute-force approach runs in O(N^3) time where N is the size of the
    // maximum vector size we want to test again. This might need reconsidering if
    // MaskWebSocketFramePayload() is ever optimised for a dedicated vector
    // architecture.
    TEST(WebSocketFrameTest, MaskPayloadAlignment)
    {
        // This reflects what might be implemented in the future, rather than
        // the current implementation. FMA3 and FMA4 support 256-bit vector ops.
        static const size_t kMaxVectorSizeInBits = 256;
        static const size_t kMaxVectorSize = kMaxVectorSizeInBits / 8;
        static const size_t kMaxVectorAlignment = kMaxVectorSize;
        static const size_t kMaskingKeyLength = WebSocketFrameHeader::kMaskingKeyLength;
        static const size_t kScratchBufferSize = kMaxVectorAlignment + kMaxVectorSize * 2;
        static const char kTestMask[] = "\xd2\xba\x5a\xbe";
        // We use 786 bits of random input to reduce the risk of correlated errors.
        static const char kTestInput[] = {
            "\x3d\x77\x1d\x1b\x19\x8c\x48\xa3\x19\x6d\xf7\xcc\x39\xe7\x57\x0b"
            "\x69\x8c\xda\x4b\xfc\xac\x2c\xd3\x49\x96\x6e\x8a\x7b\x5a\x32\x76"
            "\xd0\x11\x43\xa0\x89\xfc\x76\x2b\x10\x2f\x4c\x7b\x4f\xa6\xdd\xe4"
            "\xfc\x8e\xd8\x72\xcf\x7e\x37\xcd\x31\xcd\xc1\xc0\x89\x0c\xa7\x4c"
            "\xda\xa8\x4b\x75\xa1\xcb\xa9\x77\x19\x4d\x6e\xdf\xc8\x08\x1c\xb6"
            "\x6d\xfb\x38\x04\x44\xd5\xba\x57\x9f\x76\xb0\x2e\x07\x91\xe6\xa8"
        };
        static const size_t kTestInputSize = arraysize(kTestInput) - 1;
        static const char kTestOutput[] = {
            "\xef\xcd\x47\xa5\xcb\x36\x12\x1d\xcb\xd7\xad\x72\xeb\x5d\x0d\xb5"
            "\xbb\x36\x80\xf5\x2e\x16\x76\x6d\x9b\x2c\x34\x34\xa9\xe0\x68\xc8"
            "\x02\xab\x19\x1e\x5b\x46\x2c\x95\xc2\x95\x16\xc5\x9d\x1c\x87\x5a"
            "\x2e\x34\x82\xcc\x1d\xc4\x6d\x73\xe3\x77\x9b\x7e\x5b\xb6\xfd\xf2"
            "\x08\x12\x11\xcb\x73\x71\xf3\xc9\xcb\xf7\x34\x61\x1a\xb2\x46\x08"
            "\xbf\x41\x62\xba\x96\x6f\xe0\xe9\x4d\xcc\xea\x90\xd5\x2b\xbc\x16"
        };
        static_assert(arraysize(kTestInput) == arraysize(kTestOutput),
            "output and input arrays should have the same length");
        std::unique_ptr<char, base::AlignedFreeDeleter> scratch(static_cast<char*>(
            base::AlignedAlloc(kScratchBufferSize, kMaxVectorAlignment)));
        WebSocketMaskingKey masking_key;
        std::copy(kTestMask, kTestMask + kMaskingKeyLength, masking_key.key);
        for (size_t frame_offset = 0; frame_offset < kMaskingKeyLength;
             ++frame_offset) {
            for (size_t alignment = 0; alignment < kMaxVectorAlignment; ++alignment) {
                char* const aligned_scratch = scratch.get() + alignment;
                const size_t aligned_len = std::min(kScratchBufferSize - alignment,
                    kTestInputSize - frame_offset);
                for (size_t chunk_size = 1; chunk_size < kMaxVectorSize; ++chunk_size) {
                    memcpy(aligned_scratch, kTestInput + frame_offset, aligned_len);
                    for (size_t chunk_start = 0; chunk_start < aligned_len;
                         chunk_start += chunk_size) {
                        const size_t this_chunk_size = std::min(chunk_size, aligned_len - chunk_start);
                        MaskWebSocketFramePayload(masking_key,
                            frame_offset + chunk_start,
                            aligned_scratch + chunk_start,
                            this_chunk_size);
                    }
                    // Stop the test if it fails, since we don't want to spew thousands of
                    // failures.
                    ASSERT_TRUE(std::equal(aligned_scratch,
                        aligned_scratch + aligned_len,
                        kTestOutput + frame_offset))
                        << "Output failed to match for frame_offset=" << frame_offset
                        << ", alignment=" << alignment << ", chunk_size=" << chunk_size;
                }
            }
        }
    }

    // "IsKnownDataOpCode" is currently implemented in an "obviously correct"
    // manner, but we test is anyway in case it changes to a more complex
    // implementation in future.
    TEST(WebSocketFrameHeaderTest, IsKnownDataOpCode)
    {
        // Make the test less verbose.
        typedef WebSocketFrameHeader Frame;

        // Known opcode, is used for data frames
        EXPECT_TRUE(Frame::IsKnownDataOpCode(Frame::kOpCodeContinuation));
        EXPECT_TRUE(Frame::IsKnownDataOpCode(Frame::kOpCodeText));
        EXPECT_TRUE(Frame::IsKnownDataOpCode(Frame::kOpCodeBinary));

        // Known opcode, is used for control frames
        EXPECT_FALSE(Frame::IsKnownDataOpCode(Frame::kOpCodeClose));
        EXPECT_FALSE(Frame::IsKnownDataOpCode(Frame::kOpCodePing));
        EXPECT_FALSE(Frame::IsKnownDataOpCode(Frame::kOpCodePong));

        // Check that unused opcodes return false
        EXPECT_FALSE(Frame::IsKnownDataOpCode(Frame::kOpCodeDataUnused));
        EXPECT_FALSE(Frame::IsKnownDataOpCode(Frame::kOpCodeControlUnused));

        // Check that opcodes with the 4 bit set return false
        EXPECT_FALSE(Frame::IsKnownDataOpCode(0x6));
        EXPECT_FALSE(Frame::IsKnownDataOpCode(0xF));

        // Check that out-of-range opcodes return false
        EXPECT_FALSE(Frame::IsKnownDataOpCode(-1));
        EXPECT_FALSE(Frame::IsKnownDataOpCode(0xFF));
    }

    // "IsKnownControlOpCode" is implemented in an "obviously correct" manner but
    // might be optimised in future.
    TEST(WebSocketFrameHeaderTest, IsKnownControlOpCode)
    {
        // Make the test less verbose.
        typedef WebSocketFrameHeader Frame;

        // Known opcode, is used for data frames
        EXPECT_FALSE(Frame::IsKnownControlOpCode(Frame::kOpCodeContinuation));
        EXPECT_FALSE(Frame::IsKnownControlOpCode(Frame::kOpCodeText));
        EXPECT_FALSE(Frame::IsKnownControlOpCode(Frame::kOpCodeBinary));

        // Known opcode, is used for control frames
        EXPECT_TRUE(Frame::IsKnownControlOpCode(Frame::kOpCodeClose));
        EXPECT_TRUE(Frame::IsKnownControlOpCode(Frame::kOpCodePing));
        EXPECT_TRUE(Frame::IsKnownControlOpCode(Frame::kOpCodePong));

        // Check that unused opcodes return false
        EXPECT_FALSE(Frame::IsKnownControlOpCode(Frame::kOpCodeDataUnused));
        EXPECT_FALSE(Frame::IsKnownControlOpCode(Frame::kOpCodeControlUnused));

        // Check that opcodes with the 4 bit set return false
        EXPECT_FALSE(Frame::IsKnownControlOpCode(0x6));
        EXPECT_FALSE(Frame::IsKnownControlOpCode(0xF));

        // Check that out-of-range opcodes return false
        EXPECT_FALSE(Frame::IsKnownControlOpCode(-1));
        EXPECT_FALSE(Frame::IsKnownControlOpCode(0xFF));
    }

} // namespace

} // namespace net
